Newborn calves are vulnerable to lion and crocodile attacks, and rarely to leopard and hyena attack. This predation, as well as drought, contribute significantly to infant mortality. The newborn elephant, known as a calf, is fortunate to be looked after by a tight-knit group of females. After it is born, rest of the herd acknowledges it by touching her with their trunks. These females members fo the herd often place the calf in the middle of a tight circle of elephants in order to protect it from the dangers that abound on the African savanna.